The present invention relates to a door assembly that comprises a door frame assembly that mounts within an exterior doorway of a building and a door panel that opens and closes over the doorway. In particular, the present invention relates to an improved door sill assembly and an improved method for making a door sill assembly.
One of the traditional problems faced when constructing door assemblies that mount within a doorway on a building exterior is preventing water and other liquids from flowing through the door frame assembly, specifically at the lower edge thereof where the door sill assembly is located. Conventionally, door sill assemblies have used a sub-sill that is capable of receiving water and draining it out to the building exterior and the tread is provided with a weep system that allows water to flow into the sub-sill. One problem with these conventional arrangements is that the side jambs of the frame are attached to the outside of the sub-sill ends, thereby creating a potential for water to flow between the sub-sill ends and the side jambs. To solve this problem, gaskets or similar rubber seals have been provided between the side jambs and the sub-sill to prevent such leakage. These gaskets add extra cost to the door frame assembly and may still not solve the potential leakage problem if they are improperly positioned between the sub-sill ends and the side jambs. Water that leaks between the door sill assembly and the door panel can flow into the building interior and create puddles or damages floor treatments, such as carpeting. Also, some of this water may possibly leak between the door sill assembly and the building floor into the building sub-floor where over time it can cause the wood components in the building sub-floor to rot, thereby incurring the high expense associated with tearing up the building floor and re placing sub-floor components.
Another problem with some known door sill assemblies is that the sub-sills have a low fluid capacity. In high wind conditions, wind can blow into the drainage system and increase the pressure inside the sub-sill. Without a sufficient volume to accommodate this increase in pressure, the sub-sill may not function effectively to drain the fluid therein. Further, in arrangements that use grooves to guide the water to the drainage openings, such as the assembly disclosed in U.S. Pat. No. 3,900,967, the wind may displace some of the fluid and force it back out through its weepholes.
Consequently, there exists a need for a door frame assembly that includes an improved high volume door sill assembly that functions effectively to prevent water from draining into the building sub-floor. To meet this need, one aspect of the present invention provides a door frame assembly constructed and arranged to be installed in a doorway located at an exterior of a building in conjunction with a door panel movable between open and closed positions with respect to the doorway. The door frame assembly comprises first and second side jambs constructed and arranged to be mounted along first and second generally vertically extending sides of the doorway and a door sill assembly constructed and arranged to be mounted along a lower edge of the doorway between the first and second side jambs. The door sill assembly comprises a sub-sill having a peripheral wall including a bottom wall, first and second end walls extending generally upwardly from the bottom wall at opposing end portions of the sub-sill, a rear wall extending longitudinally between the end walls, and a front wall extending longitudinally between the end walls opposite the rear wall. The walls of the sub-sill provide interior surfaces that cooperate to define an open fluid-receiving trough extending between the front and rear walls and the first and second end walls. The peripheral wall has one or more openings formed therethrough to allow fluid in the trough to drain from the trough to the building exterior when the door frame assembly is installed in the doorway with the front wall facing the building exterior. The end and rear walls are constructed and arranged to prevent fluid in the trough from flowing into the building interior.
A tread structure is mounted to the sub-sill so as to cover the sub-sill. The tread structure and the sub-sill are constructed and arranged such that fluid flowing over the tread structure towards building interior is directed into the trough of the sub-sill and then is allowed to drain out from the trough to the building exterior through the one or more openings in the peripheral wall of the sub-sill. The first and second side jambs and the door sill assembly are constructed and arranged such that the first and second side jambs connect to the opposing end portions of the sub-sill with portions of the first and second side jambs extending inside the first and second end walls, respectively, and downwardly into the trough adjacent opposing end portions of the tread structure so that fluid flowing over the tread structure towards the building interior adjacent to the first and second side jambs is allowed to flow downwardly into the trough of the sub-sill between the tread structure and the side jambs and then is allowed to drain out from the trough to the building exterior through the one or more openings in the peripheral wall of the sub-sill.
Thus, it can be appreciated that the door sill assembly of the present invention provides an effective arrangement for draining water and other liquids flowing through or attempting to flow through the doorway and preventing the water or other liquids from leaking into the sub-floor between the door jambs and the sub-sill. The open trough of the sub-sill provides the door sill assembly with a relative large fluid capacity for handling fluid drainage in comparison to the prior art arrangements that use narrow grooves for guiding the fluid. The advantage of this open trough construction is that, when a high wind is blowing directly on the building exterior, the wind may blow into the sub-sill via its openings. Because of the sub-sill""s open trough arrangement, the wind can flow over the top of the water contained in the trough and out through the weepholes. This prevents the wind from creating a high pressure situation in the trough.
Related aspects of the invention also provide the door sill assembly for use in the door frame assembly, and the entire door frame assembly which includes the door panel itself.
Another aspect of the invention relates specifically to door frame assemblies of the type that are used in conjunction with a door panel that is movable between its open and closed positions in a generally rectilinear manner, such as a conventional sliding or rolling door panel. In these types of arrangements, the tread structure on the door sill assembly is typically provided with a door panel supporting lip that extends generally upwardly therefrom for supporting the rectilinearly movable door panel. Fluid flowing over the tread structure tends to become trapped behind the lip, thus providing a supply of fluid that can flow into the building interior. To obviate this problem, this aspect of the invention provides a door frame assembly constructed and arranged to be installed in a doorway located at an exterior of a building in conjunction with a door panel movable in a generally rectilinear manner between open and closed positions with respect to the doorway. The door frame assembly comprises first and second side jambs constructed and arranged to be mounted along first and second generally vertically extending sides of the doorway and a door sill assembly constructed and arranged to be mounted along a lower edge of the doorway between the first and second side jambs. The door sill assembly comprises a sub-sill having surfaces defining an interior fluid receiving space which has one or more openings to allow fluids therein to drain therefrom to the building exterior when the door frame assembly is installed in the doorway. The sub-sill is constructed and arranged to prevent fluid in the fluid receiving space from flowing into the building interior.
A tread structure is mounted to the sub-sill so as to cover the sub-sill. The tread structure and the sub-sill are constructed and arranged such that fluid flowing over the tread structure towards the building interior is directed into the fluid receiving space of the sub-sill and then is allowed to drain out to the building exterior through the one or more openings. The tread structure provides a door panel supporting lip extending generally upwardly therefrom. The lip is constructed and arranged such that the rectilinearly movable door panel can be mounted on the lip and supported thereby for generally rectilinear movement between opened and closed positions. The tread structure also has structure that cooperates with the lip to define a groove extending alongside the lip rearwardly thereof. The groove is configured to guide fluid flowing over the lip towards the opposing ends of the tread structure for drainage to the exterior of the building. The first and second side jambs and the door sill assembly are constructed and arranged such that the first and second side jambs connect to the opposing end portions of the sub-sill in such a manner that fluid flowing over the tread structure towards the building interior adjacent to the first and second side jambs is allowed to flow downwardly into the fluid receiving space of the sub-sill between the tread structure and the side jambs and then is allowed to drain out to the building exterior through the one or more openings.
Related aspects of the invention also provide the door sill assembly for use in the door frame assembly, and the entire door frame assembly which includes the door panel itself.
Another aspect of the invention relates to a method for making a door sill assembly. Typically, the sub-sill is injection molded as one piece and then the tread structure is extruded, cut to a length corresponding to the length of the sub-sill, and assembled to the sub-sill. The problem with this conventional method is that it is not cost-effective for constructing door sill assemblies of varying lengths. Specifically, doorways usually come in a standard number of widths and it is desirable to provide door frame assemblies for each of these standard widths. To accomplish this using one-piece sub-sills, a separate injection molding die must be used for the sub-sill of each length of door sill assembly or separate molding cavities for sub-sill portions of different lengths must be formed in a single molding die. The tread structure does not pose a significant problem because it is extruded and may be formed to length. The costs associated with using separate injection molds for each sub-sill length, however, can be quite prohibitive.
Thus, there exists a need for an improved method of making a door sill assembly that is more cost-effective than the conventional method described above. To meet this need, another aspect of the invention provides a method for making door sill assemblies of varying lengths, the door sill assemblies being constructed and arranged to be installed along lower edges of doorways located at the exteriors of buildings in conjunction with first and second side jambs that are constructed and arranged to be installed along generally vertically opposing sides of the doorways. The method comprises forming a plurality of first sub-sill portions each having generally the same length and forming a plurality of second sub-sill portions of varying lengths including at least (a) second sub-sill portions each having a first length that will provide a first completed sub-sill with a first predetermined total length selected to extend along the lower edge of a selected doorway between first and second side jambs when the second sub-sill portions having the first length are each connected to the first sub-sill portions and (b) second sub-sill portions each having a second length different from the first length that will provide a second completed sub-sill with a second predetermined total length selected to extend along the lower edge of another selected doorway between first and second side jambs when the second sub-sill portions having the second length are each connected to the first sub-sill portions. The second sub-sill portions having the first length are connected to a first multiplicity of the first sub-sill portions to form a multiplicity of first completed sub-sills each having the aforesaid first predetermined total length and the second sub-sill portions having the second length are connected to a second multiplicity of the first sub-sill portions to form a multiplicity of second completed sub-sills each having the aforesaid second predetermined total length. A plurality of tread structures of varying lengths are provided, including at least a multiplicity of first tread structures having lengths corresponding to the first predetermined total length and a multiplicity of second tread structures having lengths corresponding to the second predetermined total length. The first tread structures are connected over the first completed sub-sills so that the first tread structures cover the first completed sub-sills. The second tread structures are connected over the second completed sub-sills so that the second tread structures cover the second completed sub-sills.
It can be appreciated that making the door sill assembly in accordance with the principles of this aspect of the invention obviates the need for separate molding dies because the length of one of the sub-sill portions is selected to provide the entire sub-sill with on overall length suitable for mounting along the lower edge of the doorway. That is, the length of only one sub-sill portion is varied and the remaining sub-sill portion(s) remains fixed. The length of that one portion can be varied simply by consistently forming it in a maximum length and then cutting it down to its desired size. Alternatively, an injection mold with a cavity corresponding to the maximum size of the varied length portion may be used and inserts can be placed in the mold to provide the portion with varying sizes.
Other objects, advantages, and features of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.